Anyone put 33" wheels on a Tomytec drive?

[wcfn100]

I have a project that would require a drive truck with a 7' 4" wheelbase which the Tomytec TM-01 through -04 are supposed to have but they also have 35" wheels and huge flanges ( and a pretty wide tread it looks like).  I'd need 33" wheels and was wondering if anyone has done this.

Jason

[sd45elect2000]

I need the smaller flanges and finer scale wheels too.

http://www.proto87.com/Street_track_for_trolleys_and_trams.html

Randy

[cjm413]

Bachmann mechanism?

http://www.spookshow.net/loco/doodbug.html

[wcfn100]

Bachmann mechanism?

http://www.spookshow.net/loco/doodbug.html

The Bachmann drive is too short at around 6' 8".

Jason

[randgust]

There are various Tomytec drives with 12mm, 13mm and 14mm truck wheelbases.    Plaza Japan shows specs on their descriptions for the various chassis.

Tomytec wheels are very easy to turn the flanges smaller with a file as they are all split-axle.

[peteski]

If they have split axles then you might be able to replace them with Kato wheels, if the axles are the same diameter.   IIRC, Kato caboose wheels were 33" and had split-axles.  While not exactly low-profile or narrow-tread, they are probably finer than Tomix.

[narrowminded]

I currently have wheels with split axles made for my mine, PCC, and miniature power truck projects with 1.2mm axles.  That is probably small for Bachmann or Kato but I don't know about Tomy Tek.  I have in N scale: 24", 26", and 33" to RP-25 standards.  In Nn3 (Z) I have 24" and 33" to RP-25 standards (Z 33" and 45") and also a wide Nn3 (Z) version in both sizes which is the same RP-25 standard but to N scale tread widths.  All are nickel silver and dimensionally are extremely accurate.  A .010" gap between the axles puts the wheels in perfect gauging.

They are plain front face as they will have various features machined into those faces depending on the application and visibility.    Currently planned are typical dished, dished with relief holes, drilled for driving rods, and hex nut centers in the 26" N scales for the PCC.  Some will be used as is with the plain face.  Others will be added as the need arises.

[peteski]

I currently have wheels with split axles made for my mine, PCC, and miniature power truck projects with 1.2mm axles.  That is probably small for Bachmann or Kato but I don't know about Tomy Tek.  I have in N scale: 24", 26", and 33" to RP-25 standards.

Kato uses 1mm (0.98mm on my caliper) half-axles and Bachmann tender trucks have 1.2mm (1.18mm) half axles.

[narrowminded]

Kato uses 1mm (0.98mm on my caliper) half-axles and Bachmann tender trucks have 1.2mm (1.18mm) half axles.

Early in my research testing motor and drive combinations for feasibility of such a small power truck I had some Fox Valley N scale metal wheels laying about and so used them in a rigged test chassis.  They were the standard pointed axle and the end that pressed into the wheel was 1.2mm so I used that dimension on some 1.2mm axles that I made.  They worked well, kept the diameter down from the prevailing 1.5mm dimension or more which was at the heart of my biggest concerns, that of the ever present problem of split gears and compounding my concern was my gears were even smaller diameter than those with the splitting problem.  Added to that was unnecessary power consumption/ mechanical loss of an oversized bearing.  So when the time came to make my own one piece wheels I just stayed with the 1.2mm.  It had proven to have ample retaining and driving friction for the gear press fit, enough strength to not readily bend when handling during assembly and maintenance, and kept the axle circumference down for acceptable bearing friction.  It just seemed to be the right balance for a robust enough design without being overkill so I went with it.

[peteski]

I provided the diameters of Kato and Bachmann half-axles simply because in your post , by using the word "probably", you seemed to be unsure of their size.

That is probably small for Bachmann or Kato but I don't know about Tomy Tek.

[narrowminded]

I provided the diameters of Kato and Bachmann half-axles simply because in your post , by using the word "probably", you seemed to be unsure of their size.

That's true.  I didn't remember specifically which ones were which just that I knew at least a few were of those sizes and were also the likely brands based on stuff I had.  I'm relatively new at this especially at the intimate level and am working from a design and build devices knowledge base not specific to trains and such.  You guys who've been at this stuff and kit bashing and fixing and patching and rail fanning and... have it all over me in this kind of knowledge.  I've learned a lot from reading many of these posts.  I'm more of a "parts is parts, what are you trying to do?" guy.   But I do have those wheels as described.

[narrowminded]

This exchange got me to thinking.  It hurt but I am over it now.

If those axles ARE 1.5mm, which is a good possibility based on other typicals, you could make up what you need with Fox Valley wheelsets.  As I mentioned and as I recalled, they are turned down to 1.2mm where the wheel presses on BUT... I just measured one and the axle across the span IS 1.5mm and only one side is insulated SO... you could cut the axles in half and use the non insulated half for your wheel.  And because that's not a unique way to assemble wheels there may be other combinations available by checking other brands of wheelsets.  And worst case, if this had you stuck, I would be willing to make up something to get you going. 

For machine time I used to have to take advantage of access at a customer's shop but because it's a busy shop access was less than I (and the owner) had hoped.  It had my projects slowed to slower than a crawl (years now) with no end in sight so I finally committed and picked up a few small machines so I can prototype at home.  I got stuff up and running last week and while there's still set-up and tooling details to finish I actually made parts this week (and am THRILLED).  Good luck.

[Lemosteam]

And with the leftover FVM ends you could make a bunch of fully isolated axles using these:



https://www.shapeways.com/product/FWTVUSLA2/n-scale-axle-muff-20pk-for-fvm-axles?optionId=59767366

[randgust]

I've probably got six different Tomytec chassis laying around, give me a day and I'll have the measurements back to you.

They have both interior pickup and end-axle pickup on different wheel designs.

I use them for both my powered boxcar kits and my Whitcomb 65-tonner so I've seen a lot of them.   I've had customers request me to turn down the flanges and I consider it one of the easier ones to do.

OK, so here's the update done with a micrometer in decimal inches.   Standard wheel OD at rim is .215, which calculates out to 34.4 inches.  I wondered about that.   If you want to go through this for 1 1/2 N inches, God bless you.

Diameter back at the flange (taper) is .218.

Diameter over the flange is .275, so the flanges work out to be .285.  Not really that much to take off - I use a Dremel and a file and my micrometer to know where to stop given a target flange depth.

Behind the wheel, the shoulder measures .092 in diameter and .127-.077 so .050

The half-axle measures .042 in diameter and .085 long.

Tread width .077 from wheel to back of flange; flange width .015, so .062 width.

12mm and 14mm wheelbases depending on which chassis.   It used to be just 14mm.   

Also be aware that the "R" versions center the worm above the truck wheelbase where the original ones put the worm at the end with the universal pivot at the truck center.  BIG difference - I find the original ones handle sharp curves better and are far easier to equip in a new mechanism.

[Teditor]

Randgust,

Do you have a recommendation for powered boxcars, something I am looking at doing, for 50ft Micro-Trains.